My father gave me his old samsung 40b8000 led tv. Picture was good. Then I was fool and updated firmware to last one ( T-CHU7DEUC-3002.1 date 21.04.2010). Also I changed some settings from secret menu because i wanted to turn off local dimming. Now picture is realy ugly, dark, i cant watch my sd channels because it is too dark and colours are strange (even in dymamic mod with backlight 10). Please help me and tell me what i can do to return back good picture. Thank you so much